Numbers 1:4

‘And with you (ye) there shall be a man of every tribe, every one head of his fathers' house.'

Furthermore twelve men were to be called on to assist, one from each of the twelve tribes, each to be the head of his father's house, the prince of the tribe. Each would be responsible for the ‘numbering' his tribe.

“Of his father” s house.' This is a fluid term. In this case the house of his fathers is the tribe over which he is head seen in terms of its founder. (Later it will signify the larger families which make up the clan which itself is a section of the tribe).